Method of coating metal articles



(No Model.)

F. J. CLAMER. METHOD 0F GOATING METAL ARTIGLBS.

No. 494,668. Patented Apr. 4, 1893.

F/`G.'/. i

UNITED STATES PATENT OFFICE..

FRANCIS J. CLAMER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE AJAX LEAD COATING COMPANY, OF CAMDEN, NEW JERSEY.

METHOD OF COATING METAL ARTICLES.

SPECIFICATION forming` part of Letters Patent No. 494,668, dated April 4, V1893.

Original application filed March 29, 1892. Serial No. 426,866. Divided and this application tiled .T uly 12, 1892. Serial No. 439,750. l

(No specimens.)

To all whom iv' may concern.-

Be it known that I, FRANCIS J. CLAMER, a citizen of the United States, residing at the city of Philadelphia, in the county of Philadelphia and St-ate of Pennsylvania, have invented certain new and useful Improvements in the Method of Coating Metal Articles, for,

which I filed an application for Letters Patent of the United States, Serial No. 426,866,

Io under date of March 29, 1892, of which thefollowing is a divisional specification.

My invention has relation to an improved method of coating articles of iron or steel, such as plates, bolts, wire and other articles I5 of hardware with lead or analogous material.

The principal object of my present invention is to provide an economical and expeditious method of producing a non-oxidizable coated metal article7 that is, a metal article zo completely, smoothly and permanently coated with lead or analogous material or materials and such an article as has prior to the application of the coating thereto certain material or materials applied to the same in order to 2 5 create an affinity between the coating and the article so that the latter may absorb a portion of the former and so that in the application of the coating to the article andthe subsequent drawing, rolling, forging, pressing or 3o hammering of the same,the pliability as well as the yielding or expansible properties of the article may be appreciably increased without in the least affecting the strength of the finished article.

My invention consists of the improvements in the method of producing coated metal articles hereinafter described and claimed.

The nature, scope and general characteristic features of my invention will be more fully understood from the following description taken in connection with the accompanying drawings forming part hereof; and in which Figure l, is a top or plan View of an electrolytic cell in which rust and oxide may be removed from articles to be coated. Fig. 2, is a side elevation of several tanks employed as heated baths for cleansing and washing the article. Figla, is a sectional elevation of an externally head vat in which the Washed articles are treated preparatory to the reception of the coating of lead or analogous material. Fig.

4, is a sectional elevation of an externally heated vat orkettle in whicliacoatingof molten lead or similar metallic material may be applied to the cleansed and treated or prepared article and also showing means for converting the molten coating into a fibrous state under pressure. Fig. 5, is a diagrammatical View, illustrating the eect produced by the application of pressure to the article having the 5o coating of lead or analogous metallic material applied thereto. Fig. 6, is a top or plan view of the coated article illustrated in Fig. 4. Figs. 7 and 8 are views, illustrating the effect produced by forging the coating of lead, tin, zinc or analogous metallic material after application to the metal article; and Fig. 9, is a view illustrating the effect produced by drawing a coated wire through die-plates.

According to my invention a metallic arti- 7o cle coated with lead or other metallic material is rendered dense or fibrous and the coating completely and uniformly covers the article, as is shown at a, in Figs. 4, 5, 6, 7 and 8, in contradistinction to an article in which the coating is crystalline, as is indicated at b, and consequently porous as at c.

An article produced according to my invention is impervious to or protected from the corrosive action of the atmosphere and of 8o various liquidsv and gases, because the continuous, imporous coating protectsit from the same, whereas an article provided with a crystalline coating is readily oxidized and subject to corrosion under similar circumstances as stated, because liquids and gases are afforded free access to the same by reason of the existence of the pores or uncoated portion c. Moreover, an article made according to my invention presents a metallic luster, while an 9o article having a porous surface or a crystalline coating applied thereto presents a dull unsightly appearance as well as a rough and irregular surface; and moreover, according to my invention a strong affinity exists between the coating and the metal of the article and thus through such affinity the coating becomes a part of the metal or base of the article, thereby rendering the finished or coated metal article, fibrous and absolutely rust roo proof or non-corrosive under the influence of the atmosphere and gases or liquids.

In practice it has been found after costly experiments that it is exceedingly advantageous that an affinity be created of the coating for the metal article, and it has been found that this result can beattainedby the application of a suitable proportion of phosphorus with or without other ingredients to the snrface of the metal article. This phosphorus may be applied by immersing the articles in a bath of phosphor-lead or phosphide of lead or other salts containing phosphorus may be mixed With suitable or appropriate solvents and then applied in the form of Ya bath to the metal article. By these means excellent results can be obtained, because the phosphorus gives rise to asti-ong affinity bctween the coating and the metal article to which the same is applied.

A metallic article having a continuous and uniform coating of dense imperforate or fibrous lead or similar metallic 'material `may be produced according to my invention intthe following mannerz-After the article has been covered with a coating of molten lead or analogous metallic material or materials, it is rolled or drawn as illustrated in Figs. li, 5, and 9.or hammered as illustrated in Figs. 7 and S or otherwise forged With theresult that the coating is converted into a fibrous, dense or imperforate state or conditionand the coating is thus distributed uniformly, smoothly, completely and permanently over the entire surface of the metal article.

For the sake of a further explanation of my invention, I will describe in connection with the drawings a practically efficient method for the production of lead coated iron roofing plates, and from such description others skilled in the art of coating metals will be enabled to understand and practice my inven` tion in its application to other metals, such as steel Without the exercise of invention. Theiron roofing plate d is mounted upon the insulating ribsf, and is constituted the anode and a metallic lining e, the cathode, in an electrolytic vase or cellf, containing an acid electrolyte, comprising preferably Water acidulated with sulphuric and tluorhydric acids. The ensuing electrolytic action thoroughly cleanses the surfaces of the iron plates and removes all oxide or oxides therefrom. The proportion of acidsemployed in the electrolytic bath Varies and will depend upon the quality and condition of the iron plates. However, good results have been attained by the employment of live (5%) per cent. by Weight, more or less, of sulphuric and iuorhydric acids. After the plate (l has been electrolytically cleansed in the manner hereinbefore described, itis washed in a series of tanks g, containing preferably Water acidulated with fifteen (1.5%) per cent., more or less, byweight of hydrochloric acid and heated to a temperature of about 110"v Fahrenheit by means of steam pipes g', or in any preferred manner. The chemically cleansed and washed plate is then immersed in an externally heated kettle g2, containing a bath. The object of this bath is to` createin the article anA aiiinity for the coatingof lead or analogous material, and the pri ncipal constituentor active elementof this bath is phosphorus. In the present instance the phosphorusis employed ina solution of phosphide of lead; however, other compounds of phosphorus and their corresponding or appropriate solvents may be employed. The plate is Vthen immersed in an externally heated vat or kettle h, containing molten lead or analogous material, sal-ammoniac, phosphorus and arsenic With or Withoutborax 0r other similar iiuxvvhich.permeates the pores of the `plate by reason of the previous treatment of `the same in the phosphorous bath. The plate is drawn from this vat or kettle 7L, by means of feed rolls t', and is covered with a porous crystalline lumpy coating b. The plate el, is then allowed to traverse the guides j, and is `delivered between squeeze or pressure rolls 7c, which not only serve to reduce the gagethick- TOO The herein described method of coating a metal article with ibrous or imporous lead or analogous material, which consists in cleansing the article by lnaking it the anode in an electrolytic cell, then Washing and cleansing the article inbaths containing Water and hydrochloric acid, then applying to the article phosphor-lead or phosphide of lead to create an atlinity of the metal for the coating subsequently applied thereto, then coating the article with lead or `analogous material and then subjecting the coated metal article to pressure, whereby the pliability and yielding or expansible properties of the iinished coated metal article are enhanced without affecting the strength thereof.

In testimony whereof I have hereunto set my signature in the presence of two subscribing witnesses.

FRANCIS J. CLAMER. lVitnesses:

THOMAS M. SMITH, RICHARD C. MAXWELL.

III)

IZO 

